Automatic ventilator for closed carriages



F sh 211, 1959 1B. .10. HUGHES ET AL I 9 3 AUTOMATIC VENTILATOR FOR CLOSED CARRIAGES Filed May 9, 1946 F/Gl.

' lnven/om Patented Feb. 21, 1950 AUTOMATIC VENTILATOR Foa CARRIAGES CLOSED Benjamin Donald HughcsandErnest Leonard Ford, LondonEngland Application May 9, 1946, Serial No. 668,588 In Great Britain May 29, 1945 3 Claims. (01.198 20) This invention relates to automatic ventilators for closed carriages and particularly to ventilators of the ejector type disclosed in the specification to Letters Patent No. 1,568,373 and it has for its object a construction which is highly efficient, simple to construct and has no moving or loose parts liable to get out of order or lost.

To attain the objects of this invention the construction and form of the exterior shape of the device is such that the air flowing over it from either end sets up a negative pressure at one set of apertures and a positive pressure at another set of apertures the aperture out of or through which the air is to be extracted is situated midway between the two sets of apertures so that an ejector action is produced b both negative and positive pressures.

According to one embodiment of this invention, the exterior shape of the device is similar to that in the prior specification referred to above, but whereas in the aforesaid specification, the device was composed of several preformed parts soldered or otherwise connected together involving considerable skill, the device constructed according to the present invention is composed of two main elements pressed and shaped into the desired form, and a pair of deflector elements connected to one of the main elements, the two main elements being assembled and secured together by bending and pressing parts of one element over onto the other element.

In the accompanying drawings which illustrate the improved ventilator:

Figure 1 is a view in side elevation.

Figure 2 is a view in end elevation.

Figure 3 is a view in plan, and

Figure 4 is a view in longitudinal section on the line IVIV Figure 3.

Referring to the drawings which illustrate an embodiment of the invention the two main elements comprise a lower or inner element 1 constituting the base and an upper or outer element 2 constituting the cover, the lower element l comprises an approximately flat plate I of lozenge shape, furnished at certain points around its periphery with narrow extensions 3. At or about the centre the plate I is provided with an oblong aperture 4 arranged at right angles to its length, the said aperture 4 being provided with an upstanding wall 5 furnished with a flared upper edge 8 and forms the outlet duct from the interior of the body. The upper or outer element 2 comprises a plate pressed into the desired domeshaped form with a flat flange 1 approximately all round the outer edge which takes the same shape as that of the lower or inner element I. Two pairs of side deflector elements 8 joined for convenience of manufacture and assembly by bridge pieces 8* are secured to the interior of the upper element 2 so that when the two main elements I and 2 are secured together bybending and pressing the narrow extensions '3 over the edge of the flange I, the deflect-or elements Bare located a short distance from the wall -5 of the duct 4 on the lower element l.

The upper element 2 has a central portion 24 and two end portions 2 which are slightly wider at the point 2 where said end portions taper downwardly as shown and the side apertures 9 are disposed immediately to the rear of said projecting portions, the side walls of the portions 2* being vertically disposed.

The cycle of operation is as follows:

1. The front pair of deflectors direct the outer air stream (or wind) over the face and top of the front pair of side apertures, thereby setting up a negative pressure area which extends from outside and adjacent these apertures to the inside of the front hollow portion of the ventilator.

2. The outer air stream continues its flow towards the rear of the ventilator and, converging, enters the hollow body of the ventilator via the rear pair of side apertures, the ends of the rear deflectors which are facing forwards assisting entry by acting as air scoops.

3. Because of the shape and restriction inside the rear hollow portion of the ventilator body, the air which has entered builds up a positive pressure area in this part of the ventilator, but owing to the presence of a similarly disposed negative pressure area within the front hollow portion of the ventilator the rearward-entering air immediately flows forwards towards this low pressure area, its velocity being increased as it does so, due to the differences in pressure between the two interior areas referred to.

4. During this last-mentioned air movement the inner air flow passes rapidly across the top of the aperture in the base plate of the ventilator which communicates directly with the interior of the vehicle, and in doing so sets up a powerful ejector action over the said aperture, air thereby extracted passing out of the ventilator to atmosphere through the front pair of side apertures, thus completing a cycle which is automatic and continuous in a wind or in a flow of air caused by the movement of the vehicle.

The flow of air through the ventilator is indicated in Figures 3 and 4, it being assumed that the ventilator is mounted on a carriage moving 3 from right to left. The full line arrows indicate the external air, the dotted line arrows indicate the air entering the ventilator through the rear apertures and the dot-and-pic line arrows indicate the air drawn from the interior of the carriage.

What we claimis:

1. An automatic ventilator for closed carriages and the like having in combination a base element comprising an approximately flat base plate of lozenge shape, an oblong transverse aperture furnished in the base plate centrally between its ends, an upstanding wall around said oblong aperture, such wall having an outwardlyfiaredupper edge; a cover element comprising a plate pressed into a dome-shaped form having downwardlyinclined tapered end portions extending from'a central portion with vertical side walls; a pair of apertures in each of said side walls arranged on either side of said oblong aperture, a deflector element :secured adjacent the inner edge :of each of the apertures in each :side :wall, said"defiector elements each being inwardly-and obliquely inelined towards theadjacent end of the cover element'and extending across the-major part ofthe adj'acentaperture.

2. An automatio ventilator forclosed carriages andi-the like as claimed in claim 1,lin which :the two end portionsofthe cover element are,:a'djacent the centre portion, :slightly wider than :the latter and project transversely .on ieither side thereof, the apertures in the side walls being disposed immediately adjacent these projecting portions.

3. An automatic ventilator for closed carriages and the like as claimed in [claim 1, in which the edge of the base plate is provided with a flange, a plurality of extensions on the edge of said fian-ge,-a flange on the cover element, the extensions on the flange of the base element being turned over onto the flange of the cover element forsecuringthe two elements together.

"BENJAIVIIN DONALD HUGHES.

ERNEST LEONARD FORD.

REFERENCES CITED Thefiollowing references are of record in the :file of "this :patent:

UNITED STATES PATENTS 

